Filters and tasks in Croquet

Croquet is a collaborative 3D platform that allows users to work together to create and share ideas. We are developing an architecture that incorporates the ideas of filters and controls for 3D to solve this problem. Our model uses the Croquet 2D portals as view filters that can modify the nature of the content displayed on the other side of the filter. Another problem is that this collaborative sharing of interfaces tends to be complex. A new approach to this, an extension of the model-view-controller approach pioneered in Smalltalk is described. This extension of MVC to collaborative 3D user interface design consists of interactors, tasks, and replicants. This architecture solves the collaboration UI problem in a way that makes it quite easy for the designer to create robust multi-user applications without having to manage the divergent states and goals of each user. The programmer can focus on the design of an extensible system as if he is dealing with a single user.